The resistance of potato genotypes to Diabroticaspeciosa (Germar,1824) (Coleoptera: Chrysomelidae), was evaluated under field and laboratory conditions. The field trial was set up in the experimental farm of FCAV - UNESP, Jaboticabal, SP, and the following genotypes were compared: Achat, NYL 235-4, 288.759-16, 288.771-6, 288.776-3, 288.776-6, 288.787-5, 288.801-8 e 288.814-7. The leaf area consumption by adults was evaluated at 70 and 90 days after planting, and, after harvest, larval damage to tubers (number of perforations) was assessed. In the laboratory, feeding preference trials were conducted 40 days after plant emergence in no choice tests, for all nine genotypes, and at 47 and 68 days, in no choice and free choice tests, using five select genotypes. In the field test, the genotypes 288.759-16, 288.776-3, 288.776-6, 288.787-5 e 288.814-7 were less attacked by adults. However, 288.759-16 and 288.776-6 did not show this performance under laboratory conditions. NYL 235-4 and 288.801-8 were resistant to larval tuber damage. The genotype 288.776-3 showed resistance to larva e and adults of Diabrotica speciosa, and feeding nonpreference was the resistance mechanism to the adults.
Insecta; host plant resistance; antixenosis; feeding preference
